[Python-Dev] Adding a conditional expression in Py3.0 (original) (raw)

Steve Holden steve at holdenweb.com
Thu Sep 29 23:32:06 CEST 2005

Guido van Rossum wrote:

On 9/29/05, Steve Holden <steve at holdenweb.com> wrote:

I would argue for mandatory parentheses around the expression, leaving room later (probably after Guido is no longer around to be sick at the site of it) for:

def f(condition): return something if condition # no else! return somethingElse not-expecting-this-to-fly-ly y'rs - steve Let me give you what you expect. If all the "X if C else Y" syntax does is prevent that atrocity from ever being introduced, it would be worth it. :) Well, fine. However, it does allow atrocities like

func(f for f in lst if f > -1 if f < 0 else +1)

I realise that any chosen syntax is subject to abuse, but a conditional expression in a (currently allowed) conditional context will be guaranteed obscure. Your original instinct to omit conditional expressions was right!

far-too-late-ly y'rs - steve

Steve Holden +44 150 684 7255 +1 800 494 3119 Holden Web LLC www.holdenweb.com PyCon TX 2006 www.python.org/pycon/

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